75 
of Edinburyh, Session 1884 - 85 . 
" I certainly think so. Indeed, even apart from the context, 
I thought the Clarissimus was ironical, but there can be no doubt 
of it when it corresponds to D , Wren/’ 
In explanation of this I must mention that, when I first sent the 
passage to Prof. Butcher, I had copied it from Horsley’s sumptuous 
edition ; in which the Ds are omitted, while the Clarissimus 
is retained. 
Alike in Prance and in Germany, to this day, the Law in question 
goes by the name of Mariotte. The following extracts, from two of 
the most recent high-class text books, have now a peculiar interest. 
I have put a word or two of each in Italics. These should be com- 
pared with the dates given. 
“Diese Prage ist schon friihzeitig untersucht und zwar fast 
gleichzeitig von dem franzosischen Physiker Mariotte (1679) und dem 
englischen Physiker Boyle (1662),” Wiillner, Lehrbuch dev 
Experimentalphysik , 1882, § 98. 
“ La .loi qui regit la compressibility des gaz a temperature 
constante a ete trouvee presque simultanement par Boyle (1662) en 
Angleterre et par Mariotte (1676) en Prance; toutefois, si Boyle a 
publie le premier ses experiences, il ne sut pas en tirer Tenoned 
clair que donna le physicien frangais, C’est done avec quelque 
raison que le nom de loi de Mariotte a passd dans Tusage.” Violle, 
Cours de Physique , 1884, § 283. 
On this I need make no remark further than quoting one sentence 
from Boyle, where he compares the actual pressure, employed in 
producing a certain compression in air, with “ what the pressure 
should be according to the Hypothesis , that supposes the pressures 
and expansions to be in reciprocal proportion.” M. Violle has pro- 
bably been misled by the archaic use of “ expansion ” for volume. 
It must be said, in justice to Mariotte, that he does not appear 
to have claimed the discovery of any new facts in connection either 
with collision or with the effect of pressure on air. He rather 
appears to write with the conscious infallibility of a man for whom 
nature has no secrets. And he transcribes, or adapts, into his 
writings (without any attempt at acknowledgment) whatever suits 
him in those of other people. He seems to have been a splendidly 
successful and very early example of the highest class of what we 
now call the Paper-Scientists . Witness the following extracts from 
